西藏扎布耶盐湖卤水演化的Pitzer模型模拟

Simulation with Pitzer Model of Lake Brine Evolution of Zabuye Salt Lake,Tibetan Plateau

扎布耶盐湖是西藏高原代表性的富锂硼碳酸盐型盐湖。本文利用Pitzer模型模拟计算了西藏扎布耶盐湖冬季与夏季卤水、补给河流-泉水的低温(2℃)、常温(25℃)和高温(50℃)蒸发结晶过程,结果表明,扎布耶盐湖卤水可以由现代成分的河流-泉水蒸发浓缩形成,扎布耶盐湖的沉积组合与河泉水蒸发浓缩的矿物结晶规律吻合;而冬、夏卤水蒸发模拟结果与卤水蒸发实验结果基本吻合,但对矿物结晶顺序、矿物组合规律以及温度-季节性成分变化的影响等方面,提供了更多更详细的数据与认识。说明Pitzer模型对研究西藏富锂硼碳酸盐型盐湖的地球化学成因和盐田工艺都具有重要参考价值。

Zabuye salt lake is riched in boron and lithium with typical carbonate type brine on Tibetan Plateau. Here we simulates the evaporating erystalization process of the winter lake brine, summer lake brine, and feeding water of river and spring under 2℃, 25℃ and 50℃ using Pitzer model. The result indicates that the lake brine may origin from the evaporating concentration of river-spring water. The sedimentary assoeiation of Zabuye salt lake is similar to the evaporating erystalizing assemblage of river and spring water calculated by the model. The modeling results of winter and summer lake brine under 2℃, 25℃ and 50℃ is basicly similar to pan evaporation experiment, but give more detail and quantitative data about the order of erystalization, the assemblage of minerals, and the influence of seasonal fluctuation of temperature and brine component on the evaporating erystalization. It showes that Pitzer model has great value in the study of geochemical evolution of saline lakes and solar pond evaporating technology.